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We consider the classic problem of computing the Longest Common Subsequence (LCS) of two strings of length $n$. While a simple quadratic algorithm has been known for the problem for more than 40 years, no faster algorithm has been found…

Data Structures and Algorithms · Computer Science 2021-06-16 Karl Bringmann , Vincent Cohen-Addad , Debarati Das

The longest common substring problem consists in finding a longest string that appears as a (contiguous) substring of two input strings. We consider the dynamic variant of this problem, in which we are to maintain two dynamic strings $S$…

Data Structures and Algorithms · Computer Science 2026-04-09 Panagiotis Charalampopoulos , Paweł Gawrychowski , Karol Pokorski

The edit distance between two rooted ordered trees with $n$ nodes labeled from an alphabet~$\Sigma$ is the minimum cost of transforming one tree into the other by a sequence of elementary operations consisting of deleting and relabeling…

Data Structures and Algorithms · Computer Science 2017-03-28 Karl Bringmann , Paweł Gawrychowski , Shay Mozes , Oren Weimann

Sublinear time quantum algorithms have been established for many fundamental problems on strings. This work demonstrates that new, faster quantum algorithms can be designed when the string is highly compressible. We focus on two popular and…

Data Structures and Algorithms · Computer Science 2023-02-15 Daniel Gibney , Sharma V. Thankachan

We revisit classic string problems considered in the area of parameterized complexity, and study them through the lens of dynamic data structures. That is, instead of asking for a static algorithm that solves the given instance efficiently,…

Data Structures and Algorithms · Computer Science 2022-05-03 Jędrzej Olkowski , Michał Pilipczuk , Mateusz Rychlicki , Karol Węgrzycki , Anna Zych-Pawlewicz

Many problems that can be solved in quadratic time have bit-parallel speed-ups with factor $w$, where $w$ is the computer word size. For example, edit distance of two strings of length $n$ can be solved in $O(n^2/w)$ time. In a reasonable…

Quantum Physics · Physics 2023-02-07 Massimo Equi , Arianne Meijer-van de Griend , Veli Mäkinen

In many applications, it is necessary to determine the string similarity. Edit distance[WF74] approach is a classic method to determine Field Similarity. A well known dynamic programming algorithm [GUS97] is used to calculate edit distance…

Data Structures and Algorithms · Computer Science 2007-05-23 Qi Xiao Yang , Sung Sam Yuan , Lu Chun , Li Zhao , Sun Peng

The edit distance of two strings is the minimum number of insertions, deletions, and substitutions of characters needed to transform one string into the other. The textbook dynamic-programming algorithm computes the edit distance of two…

Data Structures and Algorithms · Computer Science 2023-10-25 Alejandro Cassis , Tomasz Kociumaka , Philip Wellnitz

The Fr\'echet distance is a well-studied and very popular measure of similarity of two curves. The best known algorithms have quadratic time complexity, which has recently been shown to be optimal assuming the Strong Exponential Time…

Computational Geometry · Computer Science 2014-08-07 Karl Bringmann , Marvin Künnemann

We consider the canonical generalization of the well-studied Longest Increasing Subsequence problem to multiple sequences, called $k$-LCIS: Given $k$ integer sequences $X_1,\dots,X_k$ of length at most $n$, the task is to determine the…

Computational Complexity · Computer Science 2020-04-10 Lech Duraj , Marvin Künnemann , Adam Polak

Fine-grained reductions have established equivalences between many core problems with $\tilde{O}(n^3)$-time algorithms on $n$-node weighted graphs, such as Shortest Cycle, All-Pairs Shortest Paths (APSP), Radius, Replacement Paths, Second…

Data Structures and Algorithms · Computer Science 2020-05-07 Andrea Lincoln , Virginia Vassilevska Williams , Ryan Williams

Longest common subsequence (LCS) is one of the most fundamental problems in combinatorial optimization. Apart from theoretical importance, LCS has enormous applications in bioinformatics, revision control systems, and data comparison…

Data Structures and Algorithms · Computer Science 2020-03-17 MohammadTaghi Hajiaghayi , Masoud Seddighin , Saeed Seddighin , Xiaorui Sun

The Longest Common Subsequence (LCS) of two strings is a fundamental string similarity measure with a classical dynamic programming solution taking quadratic time. Despite significant efforts, little progress was made in improving the…

Data Structures and Algorithms · Computer Science 2021-12-17 Negev Shekel Nosatzki

In this paper, we design new sublinear-time algorithms for solving the gap edit distance problem and for embedding edit distance to Hamming distance. For the gap edit distance problem, we give an $\tilde{O}(\frac{n}{k}+k^2)$-time greedy…

Data Structures and Algorithms · Computer Science 2020-11-17 Tomasz Kociumaka , Barna Saha

Approximate Pattern Matching is among the most fundamental string-processing tasks. Given a text $T$ of length $n$, a pattern $P$ of length $m$, and a threshold $k$, the task is to identify the fragments of $T$ that are at distance at most…

Data Structures and Algorithms · Computer Science 2024-10-10 Tomasz Kociumaka , Jakob Nogler , Philip Wellnitz

String similarity, longest common subsequence and shortest edit scripts are the triplets of problem that related to each other. There are different algorithms exist to generate edit script by solving longest common subsequence problem. This…

Data Structures and Algorithms · Computer Science 2022-08-19 P. Prakash Maria Liju

Dynamic time warping distance (DTW) is a widely used distance measure between time series. The best known algorithms for computing DTW run in near quadratic time, and conditional lower bounds prohibit the existence of significantly faster…

Data Structures and Algorithms · Computer Science 2019-05-27 William Kuszmaul

The edit distance between two strings is defined as the smallest number of insertions, deletions, and substitutions that need to be made to transform one of the strings to another one. Approximating edit distance in subquadratic time is…

Data Structures and Algorithms · Computer Science 2018-04-27 Mahdi Boroujeni , Soheil Ehsani , Mohammad Ghodsi , MohammadTaghi HajiAghayi , Saeed Seddighin

The Frechet distance is a well-studied and very popular measure of similarity of two curves. Many variants and extensions have been studied since Alt and Godau introduced this measure to computational geometry in 1991. Their original…

Computational Geometry · Computer Science 2014-08-01 Karl Bringmann

We study the fundamental problem of approximating the edit distance of two strings. After an extensive line of research led to the development of a constant-factor approximation algorithm in almost-linear time, recent years have witnessed a…

Data Structures and Algorithms · Computer Science 2023-12-05 Karl Bringmann , Alejandro Cassis , Nick Fischer , Tomasz Kociumaka